ABSTRACT New thermal-hydraulic models have been implemented in the PARCS v2.5 core simulator to e... more ABSTRACT New thermal-hydraulic models have been implemented in the PARCS v2.5 core simulator to enable the simulation of heat transfer between the counter-flowing moderator and coolant in supercritical water reactors. The impact of this heat transfer on the performance of an individual assembly has been demonstrated. A quarter-core model has been simulated to demonstrate how this new capability can be used to identify hot channels in the core and to design different core configurations that may reduce the hot channel effects. Future developments will couple this core simulator capability to advanced thermal-hydraulic simulation capability for full core design and transient simulation. Copyright 2006 by ASME.
ABSTRACT Three mesh adaptivity algorithms were developed to facilitate and expedite the use of th... more ABSTRACT Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.
A flexible parallel scheme for the solution of multi-group radiation diffusion on logically recta... more A flexible parallel scheme for the solution of multi-group radiation diffusion on logically rectangular meshes is presented and its performance is assessed. This scheme combines two types of parallelism: (a) the radiation groups are distributed to different processors for independent simultaneous solution and (b) the matrix equation for each radiation group is solved in parallel using the PETSc library. It is therefore possible to realize parallel speedup for problems with a range of geometry sizes/resolutions and a variation in the number of radiation groups. This scheme is implemented in the DRACO multi-physics radiation hydrodynamics code for two differencing approximations of the diffusion operator and tested over such a range of problems. Runtime, speedup and accuracy of the results are discussed.
A new and unique fuel cycle systems code has been developed. Need for this analysis tool was esta... more A new and unique fuel cycle systems code has been developed. Need for this analysis tool was established via methodical development of technical functions and requirements followed by an evaluation of existing fuel cycle codes. As demonstrated by analysis of GNEP-type scenarios, the GENIUS code discretely tracks nuclear material from beginning to end of the fuel cycle and among any
A new and unique fuel cycle systems code has been developed. Need for this analysis tool was esta... more A new and unique fuel cycle systems code has been developed. Need for this analysis tool was established via methodical development of technical functions and requirements followed by an evaluation of existing fuel cycle codes. As demonstrated by analysis of GNEP-type scenarios, the GENIUS code discretely tracks nuclear material from beginning to end of the fuel cycle and among any number of independent regions. Users can define scenarios starting with any/all existing reactors and fuel cycle facilities or with an ideal futuristic arrangement. Development and preliminary application of GENIUS capabilities in uncertainty analysis/propagation and multi-parameter optimization have also been accomplished.
GENIUS v2 is a modular extensible platform for the study of advanced nuclear fuel cycles. A great... more GENIUS v2 is a modular extensible platform for the study of advanced nuclear fuel cycles. A great deal of flexibility is available within the high-level modeling approach described here. Fundamental to GENIUS v2 is the modeling of every individual fuel cycle and reactor facility in the nuclear fuel cycle. Each facility is assumed to operate as a black box converting discrete batches of one material, with a given isotopic composition, into discrete batches of new material, with new isotopic compositions. The modular nature of this implementation allows new developers and users to implement any numerical model for achieving this conversion. GENIUS v2 employs an approach in which every facility is owned by an institution, and each institution operates in a specific region. Institutions are intended to represent a generic operating entity, whether a private corporation, a government, an international agency, etc. Regions are intended to represent any type of geo-politically defined part...
GENIUSv2 is a discrete-facilities/discrete-materials nuclear fuel cycle systems analysis tool cur... more GENIUSv2 is a discrete-facilities/discrete-materials nuclear fuel cycle systems analysis tool currently under development at the University of Wisconsin-Madison. It is designed not only to compute the capacity and mass flow data produced by other study tools but also to model the complex relationships between nuclear fuel cycle facilities; the institutions that own them; and the national, intranational, and/or transnational regions in which they operate. This paper describes novel modeling capabilities and methodological contributions present in GENIUSv2, including its treatment of the region-institution-facility hierarchy and its optimization-compatible framework. We then present a number of test problems designed to demonstrate the code's ability to closely reproduce results from another study tool (Idaho National Laboratory's VISION code) and to richly model multi-region scenarios not easily captured by the data models of other codes currently available.
ABSTRACT New thermal-hydraulic models have been implemented in the PARCS v2.5 core simulator to e... more ABSTRACT New thermal-hydraulic models have been implemented in the PARCS v2.5 core simulator to enable the simulation of heat transfer between the counter-flowing moderator and coolant in supercritical water reactors. The impact of this heat transfer on the performance of an individual assembly has been demonstrated. A quarter-core model has been simulated to demonstrate how this new capability can be used to identify hot channels in the core and to design different core configurations that may reduce the hot channel effects. Future developments will couple this core simulator capability to advanced thermal-hydraulic simulation capability for full core design and transient simulation. Copyright 2006 by ASME.
ABSTRACT Three mesh adaptivity algorithms were developed to facilitate and expedite the use of th... more ABSTRACT Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.
A flexible parallel scheme for the solution of multi-group radiation diffusion on logically recta... more A flexible parallel scheme for the solution of multi-group radiation diffusion on logically rectangular meshes is presented and its performance is assessed. This scheme combines two types of parallelism: (a) the radiation groups are distributed to different processors for independent simultaneous solution and (b) the matrix equation for each radiation group is solved in parallel using the PETSc library. It is therefore possible to realize parallel speedup for problems with a range of geometry sizes/resolutions and a variation in the number of radiation groups. This scheme is implemented in the DRACO multi-physics radiation hydrodynamics code for two differencing approximations of the diffusion operator and tested over such a range of problems. Runtime, speedup and accuracy of the results are discussed.
A new and unique fuel cycle systems code has been developed. Need for this analysis tool was esta... more A new and unique fuel cycle systems code has been developed. Need for this analysis tool was established via methodical development of technical functions and requirements followed by an evaluation of existing fuel cycle codes. As demonstrated by analysis of GNEP-type scenarios, the GENIUS code discretely tracks nuclear material from beginning to end of the fuel cycle and among any
A new and unique fuel cycle systems code has been developed. Need for this analysis tool was esta... more A new and unique fuel cycle systems code has been developed. Need for this analysis tool was established via methodical development of technical functions and requirements followed by an evaluation of existing fuel cycle codes. As demonstrated by analysis of GNEP-type scenarios, the GENIUS code discretely tracks nuclear material from beginning to end of the fuel cycle and among any number of independent regions. Users can define scenarios starting with any/all existing reactors and fuel cycle facilities or with an ideal futuristic arrangement. Development and preliminary application of GENIUS capabilities in uncertainty analysis/propagation and multi-parameter optimization have also been accomplished.
GENIUS v2 is a modular extensible platform for the study of advanced nuclear fuel cycles. A great... more GENIUS v2 is a modular extensible platform for the study of advanced nuclear fuel cycles. A great deal of flexibility is available within the high-level modeling approach described here. Fundamental to GENIUS v2 is the modeling of every individual fuel cycle and reactor facility in the nuclear fuel cycle. Each facility is assumed to operate as a black box converting discrete batches of one material, with a given isotopic composition, into discrete batches of new material, with new isotopic compositions. The modular nature of this implementation allows new developers and users to implement any numerical model for achieving this conversion. GENIUS v2 employs an approach in which every facility is owned by an institution, and each institution operates in a specific region. Institutions are intended to represent a generic operating entity, whether a private corporation, a government, an international agency, etc. Regions are intended to represent any type of geo-politically defined part...
GENIUSv2 is a discrete-facilities/discrete-materials nuclear fuel cycle systems analysis tool cur... more GENIUSv2 is a discrete-facilities/discrete-materials nuclear fuel cycle systems analysis tool currently under development at the University of Wisconsin-Madison. It is designed not only to compute the capacity and mass flow data produced by other study tools but also to model the complex relationships between nuclear fuel cycle facilities; the institutions that own them; and the national, intranational, and/or transnational regions in which they operate. This paper describes novel modeling capabilities and methodological contributions present in GENIUSv2, including its treatment of the region-institution-facility hierarchy and its optimization-compatible framework. We then present a number of test problems designed to demonstrate the code's ability to closely reproduce results from another study tool (Idaho National Laboratory's VISION code) and to richly model multi-region scenarios not easily captured by the data models of other codes currently available.
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Studying international fuel cycle robustness with the GENIUSv2 discrete facilities/materials fuel cycle systems analysis tool [in press, paper accepted] (PDF Download Available). Available from: http://www.researchgate.net/publication/228922319_Studying_international_fuel_cycle_robustness_with_the_GENIUSv2_discrete_facilitiesmaterials_fuel_cycle_systems_analysis_tool_in_press_paper_accepted [accessed Nov 5, 2015].
Studying international fuel cycle robustness with the GENIUSv2 discrete facilities/materials fuel cycle systems analysis tool [in press, paper accepted] (PDF Download Available). Available from: http://www.researchgate.net/publication/228922319_Studying_international_fuel_cycle_robustness_with_the_GENIUSv2_discrete_facilitiesmaterials_fuel_cycle_systems_analysis_tool_in_press_paper_accepted [accessed Nov 5, 2015].